Component Description: DACMC

The DACMC is a digital signal processor that consists of an internal analog/digital converter, amplifier, and tone generator.

The DACMC operates with the ignition in RUN, ACC, or OFF. Active noise control functions only operate with the ignition in RUN.

The ACM outputs voltage through the enable circuit to enable the DACMC amplifier. The ACM also uses this circuit to detect an amplifier overload condition. In the event of an amplifier overload, the DACMC modifies the voltage signal from the ACM to increase the voltage on the enable circuit to a higher level than provided by the ACM. This higher voltage level causes the ACM to momentarily reduce the audio levels on the left and right audio output channels to the DACMC to prevent clipping and speaker damage.

The DACMC receives engine rotation speed data and active noise control microphone input signals and calculates the targeted frequency needed to cancel engine noise within the passenger compartment. The DACMC outputs the engine noise cancellation frequency to all audio system speakers as fluctuating AC voltage.

The DACMC receives audio signals from the ACM when audio is being played. The DACMC amplifies these signals and sends them to all of the audio system speakers as fluctuating AC voltage. If the engine is running and the audio system is in use, the DACMC mixes the engine noise cancellation frequency signal with the audio signals from the ACM. The mixed audio signals are then sent to all of the speakers as fluctuating AC voltage.

The DACMC requires Programmable Module Installation (PMI) when it is replaced.